The present invention relates to a hybrid transmission which is applicable to a hybrid vehicle equipped with a plurality of power sources such as an internal combustion engine and a motor/generator, and more particularly to a continuously variable hybrid transmission which is capable of continuously varying a transmission ratio using a differential mechanism.
Japanese Patent Provisional Publication No. 11-301291 discloses a hybrid transmission employing a differential mechanism where two simple (single-pinion) planetary gearsets are coaxially aligned, engine output is distributed to both ring gears of the two planetary gearsets, both carriers of the two simple planetary gearsets are connected to a driveline of a vehicle, and both sun gears of the two planetary gearsets are respectively connected to two motor/generators. Further, there is provided a brake for fixing the ring gears by stopping the rotating operation of an engine, in the hybrid transmission.